<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - geometry - minecraft</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<style>
			body {
				color: #61443e;
				font-family:Monospace;
				font-size:13px;
				text-align:center;

				background-color: #bfd1e5;
				margin: 0px;
				overflow: hidden;
			}

			#info {
				position: absolute;
				top: 0px; width: 100%;
				padding: 5px;
			}

			a {

				color: #a06851;
			}

			#webglmessage {
				background:rgb(100,0,0) !important;
				color:#fff !important;
				margin-top:10em !important;
			}
			#webglmessage a { color:#fff }

		</style>
	</head>
	<body>

		<div id="container"><br /><br /><br /><br /><br />Generating world...</div>
		<div id="info"><a href="http://threejs.org" target="_blank" rel="noopener">three.js</a> - <a href="http://www.minecraft.net/" target="_blank" rel="noopener">minecraft</a> demo. featuring <a href="http://painterlypack.net/" target="_blank" rel="noopener">painterly pack</a><br />(left click: forward, right click: backward)</div>

		<script src="../build/three.js"></script>

		<script src="js/controls/FirstPersonControls.js"></script>

		<script src="js/utils/BufferGeometryUtils.js"></script>
		<script src="js/ImprovedNoise.js"></script>
		<script src="js/WebGL.js"></script>
		<script src="js/libs/stats.min.js"></script>

		<script>

			if ( WEBGL.isWebGLAvailable() === false ) {

				document.body.appendChild( WEBGL.getWebGLErrorMessage() );
				document.getElementById( 'container' ).innerHTML = "";

			}

			var container, stats;

			var camera, controls, scene, renderer;

			var worldWidth = 128, worldDepth = 128;
			var worldHalfWidth = worldWidth / 2;
			var worldHalfDepth = worldDepth / 2;
			var data = generateHeight( worldWidth, worldDepth );

			var clock = new THREE.Clock();

			init();
			animate();

			function init() {

				container = document.getElementById( 'container' );

				camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 1, 20000 );
				camera.position.y = getY( worldHalfWidth, worldHalfDepth ) * 100 + 100;

				controls = new THREE.FirstPersonControls( camera );

				controls.movementSpeed = 1000;
				controls.lookSpeed = 0.125;
				controls.lookVertical = true;

				scene = new THREE.Scene();
				scene.background = new THREE.Color( 0xbfd1e5 );

				// sides

				var matrix = new THREE.Matrix4();

				var pxGeometry = new THREE.PlaneBufferGeometry( 100, 100 );
				pxGeometry.attributes.uv.array[ 1 ] = 0.5;
				pxGeometry.attributes.uv.array[ 3 ] = 0.5;
				pxGeometry.rotateY( Math.PI / 2 );
				pxGeometry.translate( 50, 0, 0 );

				var nxGeometry = new THREE.PlaneBufferGeometry( 100, 100 );
				nxGeometry.attributes.uv.array[ 1 ] = 0.5;
				nxGeometry.attributes.uv.array[ 3 ] = 0.5;
				nxGeometry.rotateY( - Math.PI / 2 );
				nxGeometry.translate( - 50, 0, 0 );

				var pyGeometry = new THREE.PlaneBufferGeometry( 100, 100 );
				pyGeometry.attributes.uv.array[ 5 ] = 0.5;
				pyGeometry.attributes.uv.array[ 7 ] = 0.5;
				pyGeometry.rotateX( - Math.PI / 2 );
				pyGeometry.translate( 0, 50, 0 );

				var pzGeometry = new THREE.PlaneBufferGeometry( 100, 100 );
				pzGeometry.attributes.uv.array[ 1 ] = 0.5;
				pzGeometry.attributes.uv.array[ 3 ] = 0.5;
				pzGeometry.translate( 0, 0, 50 );

				var nzGeometry = new THREE.PlaneBufferGeometry( 100, 100 );
				nzGeometry.attributes.uv.array[ 1 ] = 0.5;
				nzGeometry.attributes.uv.array[ 3 ] = 0.5;
				nzGeometry.rotateY( Math.PI );
				nzGeometry.translate( 0, 0, - 50 );

				//

				var geometries = [];

				for ( var z = 0; z < worldDepth; z ++ ) {

					for ( var x = 0; x < worldWidth; x ++ ) {

						var h = getY( x, z );

						matrix.makeTranslation(
							x * 100 - worldHalfWidth * 100,
							h * 100,
							z * 100 - worldHalfDepth * 100
						);

						var px = getY( x + 1, z );
						var nx = getY( x - 1, z );
						var pz = getY( x, z + 1 );
						var nz = getY( x, z - 1 );

						geometries.push( pyGeometry.clone().applyMatrix( matrix ) );

						if ( ( px !== h && px !== h + 1 ) || x === 0 ) {

							geometries.push( pxGeometry.clone().applyMatrix( matrix ) );

						}

						if ( ( nx !== h && nx !== h + 1 ) || x === worldWidth - 1 ) {

							geometries.push( nxGeometry.clone().applyMatrix( matrix ) );

						}

						if ( ( pz !== h && pz !== h + 1 ) || z === worldDepth - 1 ) {

							geometries.push( pzGeometry.clone().applyMatrix( matrix ) );

						}

						if ( ( nz !== h && nz !== h + 1 ) || z === 0 ) {

							geometries.push( nzGeometry.clone().applyMatrix( matrix ) );

						}

					}

				}

				var geometry = THREE.BufferGeometryUtils.mergeBufferGeometries( geometries );
				geometry.computeBoundingSphere();

				var texture = new THREE.TextureLoader().load( 'textures/minecraft/atlas.png' );
				texture.magFilter = THREE.NearestFilter;

				var mesh = new THREE.Mesh( geometry, new THREE.MeshLambertMaterial( { map: texture, side: THREE.DoubleSide } ) );
				scene.add( mesh );

				var ambientLight = new THREE.AmbientLight( 0xcccccc );
				scene.add( ambientLight );

				var directionalLight = new THREE.DirectionalLight( 0xffffff, 2 );
				directionalLight.position.set( 1, 1, 0.5 ).normalize();
				scene.add( directionalLight );

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );

				container.innerHTML = "";

				container.appendChild( renderer.domElement );

				stats = new Stats();
				container.appendChild( stats.dom );

				//

				window.addEventListener( 'resize', onWindowResize, false );

			}

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

				controls.handleResize();

			}

			function generateHeight( width, height ) {

				var data = [], perlin = new ImprovedNoise(),
					size = width * height, quality = 2, z = Math.random() * 100;

				for ( var j = 0; j < 4; j ++ ) {

					if ( j === 0 ) for ( var i = 0; i < size; i ++ ) data[ i ] = 0;

					for ( var i = 0; i < size; i ++ ) {

						var x = i % width, y = ( i / width ) | 0;
						data[ i ] += perlin.noise( x / quality, y / quality, z ) * quality;


					}

					quality *= 4;

				}

				return data;

			}

			function getY( x, z ) {

				return ( data[ x + z * worldWidth ] * 0.2 ) | 0;

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function render() {

				controls.update( clock.getDelta() );
				renderer.render( scene, camera );

			}

		</script>

	</body>
</html>
